1. Field of the Invention
The present invention relates to a thin-film magnetic head comprising at least an induction-type magnetic transducer and a method of manufacturing such a thin-film magnetic head.
2. Description of the Related Art
Performance improvements in thin-film magnetic heads have been sought as surface recording density of hard disk drives has increased. Such thin-film magnetic heads include composite thin-film magnetic heads that have been widely used. A composite head is made of a layered structure including a recording head having an induction-type magnetic transducer for writing and a reproducing head having a magnetoresistive (MR) element for reading.
It is required to increase the track density on a magnetic recording medium in order to increase recording density among the performance characteristics of a recording head. To achieve this, it is required to implement a recording head of a narrow track structure wherein the width of top and bottom poles sandwiching the recording gap layer on a side of the air bearing surface is reduced down to microns or the submicron order. Semiconductor process techniques are utilized to implement such a structure.
Reference is now made to FIG. 40A to FIG. 43A and FIG. 40B to FIG. 43B to describe an example of a method of manufacturing a composite thin-film magnetic head as an example of a related-art method of manufacturing a thin-film magnetic head. FIG. 40A to FIG. 43A are cross sections each orthogonal to the air bearing surface of the thin-film magnetic head. FIG. 40B to FIG. 43B are cross sections of a pole portion of the head each parallel to the air bearing surface.
In the manufacturing method, as shown in FIG. 40A and FIG. 40B, an insulating layer 102 made of alumina (Al2O3), for example, having a thickness of about 5 to 10 xcexcm is deposited on a substrate 101 made of aluminum oxide and titanium carbide (Al2O3xe2x80x94TiC), for example. On the insulating layer 102 a bottom shield layer 103 made of a magnetic material is formed for making a reproducing head.
Next, on the bottom shield layer 103, alumina, for example, is deposited to a thickness of 100 to 200 nm through sputtering to form a bottom shield gap film 104 as an insulating layer. On the bottom shield gap film 104 an MR element 105 for reproduction having a thickness of tens of nanometers is formed. Next, a pair of electrode layers 106 are formed on the bottom shield gap film 104. The electrode layers 106 are electrically connected to the MR element 105.
Next, a top shield gap film 107 as an insulating layer is formed on the bottom shield gap film 104 and the MR element 105. The MR element 105 is embedded in the shield gap films 104 and 107.
Next, a top-shield-layer-cum-bottom-pole-layer (called a bottom pole layer in the following description) 108 having a thickness of about 3 xcexcm is formed on the top shield gap film 107. The bottom pole layer 108 is made of a magnetic material and used for both a reproducing head and a recording head.
Next, as shown in FIG. 41A and FIG. 41B, on the bottom pole layer 108, a recording gap layer 109 made of an insulating film such as an alumina film whose thickness is 0.2 xcexcm is formed. Next, a portion of the recording gap layer 109 is etched to form a contact hole 109a to make a magnetic path. On the recording gap layer 109 in the pole portion, a top pole tip 110 made of a magnetic material and having a thickness of 0.5 to 1.0 xcexcm is formed for the recording head. At the same time, a magnetic layer 119 made of a magnetic material is formed for making the magnetic path in the contact hole 109a for making the magnetic path.
Next, as shown in FIG. 42A and FIG. 42B, the recording gap layer 109 and the bottom pole layer 108 are etched through ion milling, using the top pole tip 110 as a mask. As shown in FIG. 42B, the structure is called a trim structure wherein the sidewalls of the top pole (the top pole tip 110), the recording gap layer 109, and part of the bottom pole layer 108 are formed vertically in a self-aligned manner.
Next, an insulating layer 111 made of alumina, for example, and having a thickness of about 3 xcexcm is formed on the entire surface. The insulating layer 111 is then polished to the surfaces of the top pole tip 110 and the magnetic layer 119, and flattened.
Next, on the flattened insulating layer 111, a first layer 112 of a thin-film coil is made of copper (Cu), for example, for the induction-type recording head. Next, a photoresist layer 113 is formed into a specific shape on the insulating layer 111 and the first layer 112 of the coil. Heat treatment is then performed at a specific temperature to flatten the surface of the photoresist layer 113. On the photoresist layer 113, a second layer 114 of the thin-film coil is then formed. Next, a photoresist layer 115 is formed into a specific shape on the photoresist layer 113 and the second layer 114 of the coil. Heat treatment is then performed at a specific temperature to flatten the surface of the photoresist layer 115.
Next, as shown in FIG. 43A and FIG. 43B, a top pole layer 116 is formed for the recording head on the top pole tip 110, the photoresist layers 113 and 115, and the magnetic layer 119. The top pole layer 116 is made of a magnetic material such as Permalloy. Next, an overcoat layer 117 of alumina, for example, is formed to cover the top pole layer 116. Finally, machine processing of the slider is performed to form the air bearing surface 118 of the thin-film magnetic head including the recording head and the reproducing head. The thin-film magnetic head is thus completed.
FIG. 44 is a top view of the thin-film magnetic head shown in FIG. 43A and FIG. 43B, wherein the overcoat layer 117 and the other insulating layers and insulating films are omitted.
In FIG. 43A, xe2x80x98THxe2x80x99 indicates the throat height and xe2x80x98MR-Hxe2x80x99 indicates the MR height. The throat height is the length (height) of portions of two magnetic pole layers between the air-bearing-surface-side end and the other end, the portions facing each other with a recording gap layer in between. The MR height is the length (height) of the MR element between an end of the MR element located in the air bearing surface and the other end. In FIG. 43B, xe2x80x98P2Wxe2x80x99 indicates the pole width, that is, the recording track width. In addition to the factors such as the throat height and the MR height, the apex angle as indicated with xcex8 in FIG. 43A is one of the factors that determine the performance of a thin-film magnetic head. The apex is a hill-like raised portion of the coil covered with the photoresist layers 113 and 115. The apex angle is the angle formed between the top surface of the insulating layer 111 and the straight line drawn through the edges of the pole-side lateral walls of the apex.
In order to improve the performance of the thin-film magnetic head, it is important to precisely form throat height TH, MR height MR-H, apex angle xcex8, and track width P2W as shown in FIG. 43A and FIG. 43B.
To achieve high surface recording density, that is, to fabricate a recording head with a narrow track structure, it has been particularly required that track width P2W fall within the submicron order of 1.0 xcexcm or less. It is therefore required to process the top pole into the submicron order through semiconductor process techniques.
A problem is that it is difficult to form the top pole layer of small dimensions on the apex.
As disclosed in Published Unexamined Japanese Patent Application Hei 7-262519 (1995), for example, frame plating may be used as a method for fabricating the top pole layer. In this case, a thin electrode film made of Permalloy, for example, is formed by sputtering, for example, to fully cover the apex. Next, a photoresist is applied to the top of the electrode film and patterned through a photolithography process to form a frame to be used for plating. The top pole layer is then formed by plating through the use of the electrode film previously formed as a seed layer.
However, there is a difference in height between the apex and the other part, such as 7 to 10 xcexcm or more. The photoresist whose thickness is 3 to 4 xcexcm is applied to cover the apex. If the photoresist thickness is required to be at least 3 xcexcm over the apex, a photoresist film having a thickness of 8 to 10 xcexcm or more, for example, is formed below the apex since the fluid photoresist goes downward.
To implement a recording track width of the submicron order as described above, it is required to form a frame pattern of the submicron order through the use of a photoresist film. Therefore, it is required to form a fine pattern of the submicron order on the apex through the use of a photoresist film having a thickness of 8 to 10 xcexcm or more. However, it is extremely difficult to form a photoresist pattern having such a thickness into a reduced pattern width, due to restrictions in a manufacturing process.
Furthermore, rays of light used for exposure of photolithography are reflected off the base electrode film as the seed layer. The photoresist is exposed to the reflected rays as well and the photoresist pattern may go out of shape. It is therefore impossible to obtain a sharp and precise photoresist pattern.
As thus described, it is difficult in prior art to fabricate the top pole layer with accuracy if the pole width of the submicron order is required.
To overcome the problems thus described, a method has been taken, as shown in the foregoing related-art manufacturing steps illustrated in FIG. 41A to FIG. 43A and FIG. 41B to FIG. 43B. In this method, a track width of 1.0 xcexcm or less is formed through the use of the top pole tip 110 effective for making a narrow track of the recording head. The top pole layer 116 to be a yoke portion connected to the top pole tip 110 is then fabricated (as disclosed in Published Unexamined Japanese Patent Application Sho 62-245509 [1987] and Published Unexamined Japanese Patent Application Sho 60-10409 [1985]). That is, the ordinary top pole layer is divided into the top pole tip 110 and the top pole layer 116 to be the yoke portion in this method. As a result, it is possible to reduce the dimensions of the top pole tip 110 that defines the recording track width to some extent and to form the top pole tip 110 on the flat top surface of the recording gap layer 109.
However, the following problems (1) to (3) are still found in the thin-film magnetic head having a structure as shown in FIG. 43A and FIG. 43B.
(1) In the thin-film magnetic head shown in FIG. 43A and FIG. 43B, the recording track width and the throat height are defined by the top pole tip 110. Therefore, if the recording track width is extremely reduced, that is, down to 0.5 xcexcm or less, in particular, the size of the top pole tip 110 is thus extremely reduced. As a result, pattern edges may be rounded and it is difficult to form the top pole tip 110 with accuracy. Therefore, the thin-film magnetic head having the structure as shown in FIG. 43A and FIG. 43B has a problem that it is difficult to precisely control the recording track width and the throat height if the recording track width is extremely reduced.
(2) In the thin-film magnetic head shown in FIG. 43A and FIG. 43B, the recording track width is defined by the top pole tip 110. Therefore, it is not necessary that the top pole layer 116 is processed into dimensions as small as those of the top pole tip 110. However, if the recording track width is extremely reduced, that is, down to 0.5 xcexcm or less, in particular, processing accuracy for achieving the submicron-order width is required for the top pole layer 116, too. However, the top pole layer 116 is formed on top of the apex in the head shown in FIG. 43A and FIG. 43B. Therefore, it is difficult to reduce the top pole layer 116 in size, due to the reason described above. In addition, the top pole layer 116 is required to be greater than the top pole tip 110 in width since the top pole layer 116 is required to be magnetically connected to the top pole tip 110 smaller in width. Because of these reasons, the top pole layer 116 is greater than the top pole tip 110 in width in this thin-film magnetic head. In addition, the end face of the top pole layer 116 is exposed from the air bearing surface. As a result, writing may be performed by this thin-film magnetic head on a side of the top pole layer 116, too, and so-called xe2x80x98side writexe2x80x99 may result, that is, data is written in a region of a recording medium where data is not supposed to be written, or so-called xe2x80x98side erasexe2x80x99 may result, that is, data is erased in a region of a recording medium where data is not supposed to be written. Such a problem more frequently results when the coil is two-layer or three-layer to improve the performance of the recording head and the apex is thereby increased in height, compared to the case where the coil is one-layer.
(3) In the thin-film magnetic head shown in FIG. 43A and FIG. 43B, the cross-sectional area of the magnetic path abruptly decreases in the portion in which the top pole layer 116 is in contact with the top pole tip 110. As a result, the magnetic flux is saturated in this portion. It is therefore impossible to utilize the magnetomotive force generated by the layers 112 and 114 of the coil for writing with efficiency.
Furthermore, in the prior-art thin-film magnetic head, it is difficult to reduce the magnetic path (yoke) length. That is, if the coil pitch is reduced, a head with a reduced yoke length is achieved and a recording head having an excellent high frequency characteristic is achieved, in particular. However, if the coil pitch is reduced to the limit, the distance between the zero throat height position (the position of an end of the pole portion farther from the air bearing surface) and the outermost end of the coil increases, which is a major factor that prevents a reduction in yoke length. This problem will now be described in detail. Since the yoke length of a two-layer coil can be shorter than that of a single-layer coil, a two-layer coil is adopted to many of recording heads for high frequency application. However, in the prior-art magnetic head, after the first layer of the coil is formed, a photoresist film having a thickness of about 2 xcexcm is formed to cover the first layer of the coil, so that neighboring ones of turns of the coil are insulated from each other. A rounded portion is formed near the outermost end of the photoresist layer that covers the first layer of the coil. A second layer of the coil is then formed on this photoresist layer. The second layer is required to be formed on a flat portion since it is impossible to etch the seed layer of the coil in the rounded portion near the outermost end of the photoresist layer, and the coil is thereby shorted.
Therefore, if the total coil thickness is 2 to 3 xcexcm, the thickness of the photoresist layer insulating every neighboring ones of the turns of the coil is 2 xcexcm, and the apex angle is 45 to 55 degrees, for example, the yoke length is required to be 6 to 8 xcexcm which is twice as long as the distance between the outermost end of the coil and the neighborhood of the zero throat height position, that is, 3 to 4 xcexcm (a distance of 3 to 4 xcexcm is required, too, between the innermost end of the coil and the portion where the top and bottom pole layers are in contact with each other), in addition to the length of the portion corresponding to the coil. This length of the portion except the portion corresponding to the coil is one of the factors that prevent a reduction in yoke length.
Assuming that a two-layer eleven-turn coil wherein the line width is 1.2 xcexcm and the space is 0.8 xcexcm is fabricated, for example, the portion of the yoke length corresponding to the first layer 112 of the coil is 11.2 xcexcm, if the first layer is made up of six turns and the second layer is made up of five turns, as shown in FIG. 43A and FIG. 43B. In addition to this length, the total of 6 to 8 xcexcm, that is, the distance between each of the outermost and innermost ends of the first layer 112 of the coil and each of ends of the photoresist layer 113 for insulating the first layer 112, is required for the yoke length. Therefore, the yoke length is 17.2 to 19.2 xcexcm. If a single-layer eleven-turn coil is fabricated, the yoke length is 27.2 to 29.2 xcexcm. In the present application, the yoke length is the length of a portion of the pole layer except the pole portion and the contact portions, as indicated with LO in FIG. 43A. As thus described, it is difficult in the prior art to further reduce the yoke length, which prevents improvements in high frequency characteristic.
The thin-film magnetic head shown in FIG. 43A and FIG. 43B has a flat-whorl-shaped coil. In contrast, a thin-film magnetic head having a helical-shaped coil wound around the pole layer is disclosed in U. S. Pat. No. 5,703,740, Published Unexamined Japanese Patent Application Sho 48-55718 (1973), Published Unexamined Japanese Patent Application Sho 60-113310 (1985) and Published Unexamined Japanese Patent Application Sho 63-201908 (1988), for example. Such a structure of the helical-shaped coil allows the magnetomotive force generated by the coil to be supplied to the pole layer with efficiency. As a result, it is possible that the number of turns of the coil is smaller than that of a flat-whorl-shaped coil. The yoke length is thereby reduced.
However, such a prior-art head with a helical-shaped coil has an apex, too. Therefore, the foregoing problems resulting from the apex remain unsolved.
It is an object of the invention to provide a thin-film magnetic head and a method of manufacturing the same for defining a track width and a throat height of an induction-type magnetic transducer with accuracy even when the track width is reduced, for achieving a reduction in yoke length, and for preventing writing of data in a region where data is not supposed to be written, and for preventing saturation of a magnetic flux halfway through the magnetic path.
Each of first to third thin-film magnetic heads of the invention comprises: a medium facing surface that faces toward a recording medium; a first magnetic layer and a second magnetic layer magnetically coupled to each other and including magnetic pole portions opposed to each other and placed in regions on a side of the medium facing surface, each of the magnetic layers including at least one layer; a gap layer provided between the pole portions of the first and second magnetic layers; and a thin-film coil wound around at least one of the magnetic layers in a helical manner and insulated from the first and second magnetic layers, a part of the coil passing between the first and second magnetic layers.
In the first thin-film magnetic head of the invention, one of the magnetic layers includes: a pole portion layer having a surface adjacent to the gap layer and including one of the pole portions; and a yoke portion layer connected to the other surface of the pole portion layer and making up a yoke portion. The part of the coil is located on a side of the pole portion layer. The yoke portion layer has an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. The pole portion layer includes: a track portion that defines a track width; a contact portion that is in direct or indirect contact with the yoke portion layer; and a coupling portion that couples the track portion and the contact portion to each other. The contact portion includes a plurality of branch portions that branch off from the coupling portion. The coupling portion has an end located between the branch portions and located opposite to the medium facing surface, the end defining a throat height.
According to the first thin-film magnetic head of the invention, the thin-film coil is wound around at least one of the magnetic layers in a helical manner, and a part of the coil passes between the first and second magnetic layers. In addition, the part of the coil is placed on a side of the pole portion layer of one of the magnetic layers. As a result, a reduction in the yoke length is achieved. Furthermore, the pole portion layer is formed on the flat surface, and it is thereby possible to define the track width and the throat height with accuracy. According to the first thin-film magnetic head of the invention, an end face of the yoke portion layer of the one of the magnetic layers facing toward the medium facing surface is located at a distance from the medium facing surface. The contact portion of the pole portion layer includes a plurality of branch portions that branch off from the coupling portion. The coupling portion has an end located between the branch portions and located farther from the medium facing surface. This end defines the throat height. As a result, it is possible to prevent writing of data in a region where data is not supposed to be written and to prevent a magnetic flux from saturating halfway through the magnetic path.
The first thin-film magnetic head of the invention may further comprise an insulating layer that covers the part of the coil located on the side of the pole portion layer, the insulating layer having a surface that faces the yoke portion layer and is flattened. The first thin-film magnetic head may further comprise a flux blocking layer for blocking the passage of a magnetic flux, the flux blocking layer being located between the contact portion of the pole portion layer and the other of the magnetic layers.
According to the second thin-film magnetic head of the invention, one of the magnetic layers includes: a pole portion layer having a surface adjacent to the gap layer and including one of the pole portions; a yoke portion layer making up a yoke portion; and an intermediate layer having a surface connected to the other surface of the pole portion layer, and the other surface connected to the yoke portion layer. The thin-film coil includes: a first portion a part of which is located on a side of the pole portion layer; and a second portion a part of which is located on a side of the intermediate layer. Each of the intermediate layer and the yoke portion layer has an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. The pole portion layer includes: a track portion that defines a track width; a contact portion that is in contact with the intermediate layer; and a coupling portion that couples the track portion and the contact portion to each other. The contact portion includes a plurality of branch portions that branch off from the coupling portion. The coupling portion has an end located between the branch portions and located opposite to the medium facing surface, the end defining a throat height.
According to the second thin-film magnetic head of the invention, the thin-film coil is wound around at least one of the magnetic layers in a helical manner, and includes: the first portion a part of which is located on a side of the pole portion layer; and the second portion a part of which is located on a side of the intermediate layer. As a result, a reduction in the yoke length is achieved. Furthermore, the pole portion layer is formed on the flat surface, and it is thereby possible to define the track width and the throat height with accuracy. According to the second thin-film magnetic head of the invention, each of the intermediate layer and the yoke portion layer of one of the magnetic layers has an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. The contact portion of the pole portion layer includes a plurality of branch portions that branch off from the coupling portion. The coupling portion has an end located between the branch portions and located farther from the medium facing surface. This end defines the throat height. As a result, it is possible to prevent writing of data in a region where data is not supposed to be written and to prevent a magnetic flux from saturating halfway through the magnetic path.
The second thin-film magnetic head of the invention may further comprise: a first insulating layer that covers the part of the first portion of the coil located on the side of the pole portion layer, the first insulating layer having a surface that faces the intermediate layer and is flattened; and a second insulating layer that covers the part of the second portion of the coil located on the side of the intermediate layer, the second insulating layer having a surface that faces the yoke portion layer and is flattened.
According to the third thin-film magnetic head of the invention, each of the first and second magnetic layers includes: a pole portion layer having a surface adjacent to the gap layer and including one of the pole portions; and a yoke portion layer connected to the other surface of the pole portion layer and making up a yoke portion. The thin-film coil includes: a first portion a part of which is located on a side of the pole portion layer of the first magnetic layer; and a second portion a part of which is located on a side of the pole portion layer of the second magnetic layer. The yoke portion layer of one of the magnetic layers has an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. The pole portion layer of the one of the magnetic layers includes: a track portion that defines a track width; a contact portion that is in contact with the yoke portion layer; and a coupling portion that couples the track portion and the contact portion to each other. The contact portion includes a plurality of branch portions that branch off from the coupling portion; and the coupling portion has an end located between the branch portions and located opposite to the medium facing surface, the end defining a throat height.
According to the third thin-film magnetic head of the invention, the thin-film coil is wound around at least one of the magnetic layers in a helical manner, and includes: the first portion a part of which is located on a side of the pole portion layer of the first magnetic layer; and the second portion a part of which is located on a side of the pole portion layer of the second magnetic layer. As a result, a reduction in the yoke length is achieved. Furthermore, the pole portion layer of one of the magnetic layers is formed on the flat surface, and it is thereby possible to define the track width and the throat height with accuracy. According to the third thin-film magnetic head of the invention, the yoke portion layer of one of the magnetic layers has an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. The contact portion of the pole portion layer of the one of the magnetic layers includes a plurality of branch portions that branch off from the coupling portion. The coupling portion has an end located between the branch portions and located farther from the medium facing surface. This end defines the throat height. As a result, it is possible to prevent writing of data in a region where data is not supposed to be written and to prevent a magnetic flux from saturating halfway through the magnetic path.
The third thin-film magnetic head of the invention may further comprise: a first insulating layer that covers the part of the first portion of the coil located on the side of the pole portion layer of the first magnetic layer, the first insulating layer having a surface that faces the gap layer and is flattened; and a second insulating layer that covers the part of the second portion of the coil located on the side of the pole portion layer of the second magnetic layer, the second insulating layer having a surface that faces the yoke portion layer and is flattened.
Each of first to third methods of the invention is provided for manufacturing a thin-film magnetic head comprising: a medium facing surface that faces toward a recording medium; a first magnetic layer and a second magnetic layer magnetically coupled to each other and including magnetic pole portions opposed to each other and placed in regions on a side of the medium facing surface, each of the magnetic layers including at least one layer; a gap layer provided between the pole portions of the first and second magnetic layers; and a thin-film coil insulated from the first and second magnetic layers, a part of the coil passing between the first and second magnetic layers. Each of the methods includes the steps of: forming the first magnetic layer; forming the gap layer on the first magnetic layer; forming the second magnetic layer on the gap layer; and forming the coil such that the coil is wound around at least one of the magnetic layers in a helical manner and insulated from the first and second magnetic layers, the part of the coil passing between the first and second magnetic layers.
According to the first method of the invention, the step of forming one of the magnetic layers includes the steps of forming a pole portion layer having a surface adjacent to the gap layer and including one of the pole portions; and forming a yoke portion layer connected to the other surface of the pole portion layer and making up a yoke portion. The part of the coil is located on a side of the pole portion layer in the step of forming the coil. In the step of forming the yoke portion layer, the yoke portion layer is formed to have an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. In the step of forming the pole portion layer, the pole portion layer is formed such that: the pole portion layer includes: a track portion that defines a track width; a contact portion that is in direct or indirect contact with the yoke portion layer; and a coupling portion that couples the track portion and the contact portion to each other; the contact portion includes a plurality of branch portions that branch off from the coupling portion; the coupling portion has an end located between the branch portions and located opposite to the medium facing surface, the end defining a throat height.
According to the first method of the invention, the one of the magnetic layers may be the second magnetic layer, and the method may further include the step of forming an insulating layer that covers the part of the coil located on the side of the pole portion layer, the insulating layer having a surface that faces the yoke portion layer and is flattened. The first method may further include the step of forming a flux blocking layer for blocking the passage of a magnetic flux, the flux blocking layer being located between the contact portion of the pole portion layer and the other of the magnetic layers.
According to the second method of the invention, the step of forming one of the magnetic layers includes the steps of: forming a pole portion layer having a surface adjacent to the gap layer and including one of the pole portions; forming a yoke portion layer forming a yoke portion; and forming an intermediate layer having a surface connected to the other surface of the pole portion layer, and the other surface connected to the yoke portion layer. The step of forming the coil includes formation of a first portion a part of which is located on a side of the pole portion layer; and a second portion a part of which is located on a side of the intermediate layer. In the steps of forming the intermediate layer and forming the yoke portion layer, each of the intermediate layer and the yoke portion layer is formed to have an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. In the step of forming the pole portion layer, the pole portion layer is formed such that: the pole portion layer includes: a track portion that defines a track width; a contact portion that is in contact with the intermediate layer; and a coupling portion that couples the track portion and the contact portion to each other; the contact portion includes a plurality of branch portions that branch off from the coupling portion; and the coupling portion has an end located between the branch portions and located opposite to the medium facing surface, the end defining a throat height.
According to the second method of the invention, the one of the magnetic layers may be the second magnetic layer, and the method may further include the steps of forming a first insulating layer that covers the part of the first portion of the coil located on the side of the pole portion layer, the first insulating layer having a surface that faces the intermediate layer and is flattened; and forming a second insulating layer that covers the part of the second portion of the coil located on the side of the intermediate layer, the second insulating layer having a surface that faces the yoke portion layer and is flattened.
According to the third method of the invention, each of the steps of forming the first magnetic layer and forming the second magnetic layer includes the steps of: forming a pole portion layer having a surface adjacent to the gap layer and including one of the pole portions; and forming a yoke portion layer connected to the other surface of the pole portion layer and forming a yoke portion. The step of forming the coil includes formation of: a first portion a part of which is located on a side of the pole portion layer of the first magnetic layer; and a second portion a part of which is located on a side of the pole portion layer of the second magnetic layer. In the step of forming the yoke portion layer of one of the magnetic layers, the yoke portion layer is formed to have an end face facing toward the medium facing surface, the end face being located at a distance from the medium facing surface. In the step of forming the pole portion layer of the one of the magnetic layers, the pole portion layer is formed such that: the pole portion layer includes: a track portion that defines a track width; a contact portion that is in contact with the yoke portion layer; and a coupling portion that couples the track portion and the contact portion to each other; the contact portion includes a plurality of branch portions that branch off from the coupling portion; and the coupling portion has an end located between the branch portions and located opposite to the medium facing surface, the end defining a throat height.
The third method of the invention may further include the steps of: forming a first insulating layer that covers the part of the first portion of the coil located on the side of the pole portion layer of the first magnetic layer, the first insulating layer having a surface that faces the gap layer and is flattened; and forming a second insulating layer that covers the part of the second portion of the coil located on the side of the pole portion layer of the second magnetic layer, the second insulating layer having a surface that faces the yoke portion layer and is flattened.
Other and further objects, features and advantages of the invention will appear more fully from the following description.